.I filename
read-only. This option is required if the filesystem is mounted.
It is only necessary to omit this flag if a command that changes data
-.RB ( write ", " blocktrash )
+.RB ( write ", " blocktrash ", " crc )
is to be used.
.TP
.B \-x
Specifies expert mode.
This enables the
-.B write
-and
-.B blocktrash
-commands.
+.RB ( write ", " blocktrash ", " crc
+invalidate/revalidate) commands.
.TP
.B \-V
Prints the version number and exits.
inode processed.
.RE
.TP
-.BI "blocktrash [\-n " count "] [\-x " min "] [\-y " max "] [\-s " seed "] [\-0|1|2|3] [\-t " type "] ..."
+.BI "blocktrash [-z] [\-o " offset "] [\-n " count "] [\-x " min "] [\-y " max "] [\-s " seed "] [\-0|1|2|3] [\-t " type "] ..."
Trash randomly selected filesystem metadata blocks.
Trashing occurs to randomly selected bits in the chosen blocks.
This command is available only in debugging versions of
.I count
of block-trashings to perform (default 1).
.TP
+.B \-o
+supplies the bit
+.I offset
+at which to start trashing the block. If the value is preceded by a '+', the
+trashing will start at a randomly chosen offset that is larger than the value
+supplied. The default is to randomly choose an offset anywhere in the block.
+.TP
.B \-s
supplies a
.I seed
sets the
.I maximum
size of bit range to be trashed. The default value is 1024.
+.TP
+.B \-z
+trashes the block at the top of the stack. It is not necessary to
+run
+.BI blockget
+if this option is supplied.
.RE
.TP
.BI "blockuse [\-n] [\-c " count ]
option.
.RE
.TP
-.BI "bmap [\-a\] [\-d] [" block " [" len ]]
+.BI "bmap [\-a] [\-d] [" block " [" len ]]
Show the block map for the current inode.
The map display can be restricted to an area of the file with the
.I block
.I agb
.BR fsblock .
.TP
+.B crc [\-i|\-r|\-v]
+Invalidates, revalidates, or validates the CRC (checksum)
+field of the current structure, if it has one.
+This command is available only on CRC-enabled filesystems.
+With no argument, validation is performed.
+Each command will display the resulting CRC value and state.
+.RS 1.0i
+.TP 0.4i
+.B \-i
+Invalidate the structure's CRC value (incrementing it by one),
+and write it to disk.
+.TP
+.B \-r
+Recalculate the current structure's correct CRC value, and write it to disk.
+.TP
+.B \-v
+Validate and display the current value and state of the structure's CRC.
+.RE
+.TP
.BI "daddr [" d ]
Set current address to the daddr (512 byte block) given by
.IR d .
.IR flagbits ,
print the current debug option bits. These are for the use of the implementor.
.TP
-.BI "dquot [" projectid_or_userid ]
-Set current address to a project or user quota block.
+.BI "dquot [" \-g | \-p | \-u ] " id"
+Set current address to a group, project or user quota block for the given ID. Defaults to user quota.
.TP
.BI "echo [" arg "] ..."
Echo the arguments to the output.
.B bmap
command) are in this form.
.TP
+.BI "fsmap [ " start " ] [ " end " ]
+Prints the mapping of disk blocks used by an XFS filesystem. The map
+lists each extent used by files, allocation group metadata,
+journalling logs, and static filesystem metadata, as well as any
+regions that are unused. All blocks, offsets, and lengths are specified
+in units of 512-byte blocks, no matter what the filesystem's block size is.
+.BI "The optional " start " and " end " arguments can be used to constrain
+the output to a particular range of disk blocks.
+.TP
.BI hash " string
Prints the hash value of
.I string
The possible data types are:
.BR agf ", " agfl ", " agi ", " attr ", " bmapbta ", " bmapbtd ,
.BR bnobt ", " cntbt ", " data ", " dir ", " dir2 ", " dqblk ,
-.BR inobt ", " inode ", " log ", " rtbitmap ", " rtsummary ,
+.BR inobt ", " inode ", " log ", " rmapbt ", " rtbitmap ", " rtsummary ,
.BR sb ", " symlink " and " text .
See the TYPES section below for more information on these data types.
.TP
-.BI "uuid [" uuid " | " generate " | " rewrite ]
+.BI "uuid [" uuid " | " generate " | " rewrite " | " restore ]
Set the filesystem universally unique identifier (UUID).
The filesystem UUID can be used by
.BR mount (8)
be automatically generated using the
.B generate
option. These options will both write the UUID into every copy of the
-superblock in the filesystem.
+superblock in the filesystem. On a CRC-enabled filesystem, this will
+set an incompatible superblock flag, and the filesystem will not be
+mountable with older kernels. This can be reverted with the
+.B restore
+option, which will copy the original UUID back into place and clear
+the incompatible flag as needed.
.B rewrite
copies the current UUID from the primary superblock
to all secondary copies of the superblock.
.BR xfs_logprint (8)
instead.
.TP
+.B rmapbt
+There is one set of filesystem blocks forming the reverse mapping Btree for
+each allocation group. The root block of this Btree is designated by the
+.B rmaproot
+field in the corresponding AGF block. The blocks are linked to sibling left
+and right blocks at each level, as well as by pointers from parent to child
+blocks. Each block has the following fields:
+.RS 1.4i
+.PD 0
+.TP 1.2i
+.B magic
+RMAP block magic number, 0x524d4233 ('RMB3').
+.TP
+.B level
+level number of this block, 0 is a leaf.
+.TP
+.B numrecs
+number of data entries in the block.
+.TP
+.B leftsib
+left (logically lower) sibling block, 0 if none.
+.TP
+.B rightsib
+right (logically higher) sibling block, 0 if none.
+.TP
+.B recs
+[leaf blocks only] array of reference count records. Each record contains
+.BR startblock ,
+.BR blockcount ,
+.BR owner ,
+.BR offset ,
+.BR attr_fork ,
+.BR bmbt_block ,
+and
+.BR unwritten .
+.TP
+.B keys
+[non-leaf blocks only] array of double-key records. The first ("low") key
+contains the first value of each block in the level below this one. The second
+("high") key contains the largest key that can be used to identify any record
+in the subtree. Each record contains
+.BR startblock ,
+.BR owner ,
+.BR offset ,
+.BR attr_fork ,
+and
+.BR bmbt_block .
+.TP
+.B ptrs
+[non-leaf blocks only] array of child block pointers. Each pointer is a
+block number within the allocation group to the next level in the Btree.
+.PD
+.RE
+.TP
.B rtbitmap
If the filesystem has a realtime subvolume, then the
.B rbmino
projects / thirdparty / xfsprogs-dev.git / blobdiff